Gas generator with a perforated cylinder body in a combustion chamber

Abstract

Gas generator (1) comprising, in a cylinder housing (10), a combustion chamber (20) filled with gas generating means (25, 26) as a gas source, and a gas outlet opening (16) for expelling a gas generated by the combustion of the gas generating means (25, 26), wherein the combustion chamber (20) contains an ignition device containing an igniter (11) and closing a first end opening (10a) of the cylinder housing (10), a partition wall (15) closing a second end opening (10b) on the side axially opposite the first end opening (10a), and a perforated cylinder body (21) arranged in the combustion chamber (20); wherein the igniter (11) comprises an igniter main body having an ignition portion (12) and an igniter collar (13) surrounding and holding the igniter main body; wherein the perforated cylinder body (21) is arranged such that its first end (21a) surrounds the ignition section (12) of the igniter (11) and its second end (21b) is arranged on the axially opposite side on the side of the partition wall (15); wherein an interior of the perforated cylinder body (21) is a first chamber (22) filled with a portion of the gas generating means (25), and an exterior of the perforated cylinder body (21) is a second chamber (23) filled with the remaining gas generating means (26); and at least one gas outlet opening (16) is a through hole formed in a section of the partition wall (15) facing the second chamber (23), and no gas outlet opening is formed in a region of a length of more than 0.3 from the surface of the partition wall (15) on the combustion chamber (20) side toward the first end opening (10a) in a portion of the cylinder housing (10) facing the second chamber (23) when a length from the first end opening (10a) of the cylinder housing (10) to the surface, on the combustion chamber (20) side, of the partition wall (15) closing the second end opening (10b) is set to 1, wherein the second end (21b) abuts against a surface (15a) of the partition wall (15) on the combustion chamber (20) side or is provided opposite thereto with a small gap therebetween, the small gap being a gap equal to or smaller than a diameter of holes of the perforated cylinder body (21).

Description

Subject of the invention

[0001] The present invention relates to a gas generator having a perforated cylinder body in a combustion chamber for use in an airbag device installed in a vehicle. Description of the state of the art

[0002] Fig. 1 to Fig. 4 JP H11- 78 766 A discloses a gas generator X1 in which an elongated cylinder housing 1 is used.

[0003] In the gas generator, which is Fig. 1 to Fig. 4, a combustion chamber G is divided into an inner combustion chamber G1 and an outer combustion chamber G2 by arranging a separating cylinder 20 in the combustion chamber G, the inner combustion chamber G1 and the outer combustion chamber G2 each being filled with gas generating agents 2.

[0004] It is described that in the gas generator, which is in Fig. 1 to Fig. 4, when starting an igniter 15 arranged at a position facing only the inner combustion chamber G1, the gas generating agent 2 in the inner combustion chamber G1 is burned first and the gas generating agent 2 in the outer combustion chamber G2 is burned with a delay, whereby it is possible to control a deployment speed of an airbag.

[0005] Furthermore, JP 2009-208483 A discloses a gas generator comprising a cylinder housing, a combustion chamber filled with gas generating agents, and a gas outlet opening. Furthermore, an ignition device for closing a first end opening of the cylinder housing and a partition wall for closing a second end opening are provided.

[0006] US 2006 / 0 017 270 A1 discloses a gas generator comprising a cylindrical housing, a combustion chamber filled with gas generating agents, and a gas outlet opening. Furthermore, an ignition device for closing a first end opening of the cylindrical housing and a partition wall for closing a second end opening are provided. A perforated cylindrical body is arranged in the combustion chamber, the interior of which is a first chamber and the exterior of which is a second chamber. The gas generators are stacked one above the other in the second chamber.

[0007] The object of the present invention is to provide a gas generator in which the ignitability and combustibility of gas generating agents filled in an elongated combustion chamber are improved and a combustion gas can also be easily discharged from the combustion chamber. Summary of the invention

[0008] The above object is achieved by a gas generator according to claim 1. The present invention provides a gas generator (the first aspect) comprising, in a cylinder housing, a combustion chamber filled with gas generating agents as a gas source, and a gas outlet port for discharging a gas generated by the combustion of the gas generating agents, wherein the combustion chamber contains an ignition device containing an igniter and closing a first end opening of the cylinder housing, a partition wall closing a second end opening on the side axially opposite the first end opening, and a perforated cylinder body arranged in an interior thereof; wherein the igniter comprises an igniter main body having an ignition portion and an igniter collar surrounding and holding the igniter main body; wherein the perforated cylinder body is arranged such that its first end surrounds the ignition portion of the igniter and its second end is arranged on the axially opposite side on the side of the partition wall; wherein an interior of the perforated cylinder body is a first chamber filled with a portion of the gas generating agents, and an exterior of the perforated cylinder body is a second chamber filled with the remaining gas generating agents; and wherein the gas outlet opening is a through hole formed in a portion of the partition wall facing the second chamber.

[0009] The present disclosure provides a gas generator (the second aspect) comprising, in a cylinder housing, a combustion chamber filled with gas generating agents as a gas source, and a gas discharge port for discharging a gas generated by the combustion of the gas generating agents, wherein the combustion chamber contains an ignition device containing an igniter and closing a first end opening of the cylinder housing, a partition wall closing a second end opening on the side axially opposite the first end opening, and a perforated cylinder body arranged in an interior thereof; wherein the igniter comprises an igniter main body having an ignition portion and an igniter collar surrounding and holding the igniter main body; wherein the perforated cylinder body is arranged such that its first end surrounds the ignition portion of the igniter and its second end is arranged on the axially opposite side on the side of the partition wall; wherein an interior of the perforated cylinder body is a first chamber filled with a portion of the gas generating agents, and an exterior of the perforated cylinder body is a second chamber filled with the remaining gas generating agents; and wherein the gas outlet port is a through hole formed in a portion of the cylinder housing facing the second chamber on the partition wall side.

[0010] The present disclosure provides a gas generator (the third aspect) comprising, in a cylinder housing, a combustion chamber filled with gas generating agents as a gas source, and a gas discharge port for discharging a gas generated by the combustion of the gas generating agents, wherein the combustion chamber contains an ignition device containing an igniter and closing a first end opening of the cylinder housing, a partition wall closing a second end opening on the side axially opposite the first end opening, an inner space formed therein, and a perforated cylinder body arranged in the inner space; wherein the igniter comprises an igniter main body having an ignition portion and an igniter collar surrounding and holding the igniter main body; wherein the perforated cylinder body is arranged such that a first end surrounds the ignition portion of the igniter and its second end is arranged on the axially opposite side on the side of the partition wall; wherein an interior of the perforated cylinder body is a first chamber filled with a portion of the gas generating agents, and an exterior of the perforated cylinder body is a second chamber filled with the remaining gas generating agents; wherein a diffuser portion is arranged at the second end opening of the cylinder housing which is closed by the partition wall; wherein the gas outlet opening comprises a first gas outlet opening, which is a through hole formed in a portion of the partition wall facing the second chamber, and a second gas outlet opening formed in the diffuser portion; and wherein a combustion gas generated in a combustion chamber is discharged from the first gas outlet port into the diffuser portion and then discharged from the second gas outlet port.

[0011] The present disclosure provides a gas generator (the fourth aspect) comprising a combustion chamber having a first gas outlet port and filled with gas generating agents, a diffuser chamber having a second gas outlet port, and a pressurized gas chamber in the order of description from a first end opening of a cylinder housing to a second end opening on the axially opposite side thereof; a closing element that closes between the diffuser chamber and the pressure gas chamber; a breaking device arranged between the combustion chamber and the diffuser chamber, having a base plate portion and a breaking portion and moving toward the second end opening at the time of breaking the closure member; wherein the combustion chamber contains an ignition device containing an igniter and closing a first end opening of the cylinder housing; the base plate of the breaking device closing a side opposite the first end opening; an interior space therein; and a perforated cylinder body disposed in the interior space; wherein the igniter comprises an igniter main body having an ignition portion and an igniter collar surrounding and holding the igniter main body; wherein the perforated cylinder body is arranged such that its first end surrounds the ignition portion of the igniter and its second end is arranged on the axially opposite side on the side of the partition wall; wherein an interior of the perforated cylinder body is a first chamber filled with a portion of the gas generating agents, and an exterior of the perforated cylinder body is a second chamber filled with the remaining gas generating agents; wherein the first gas outlet opening is opened to transfer a combustion gas from the combustion chamber to the diffuser chamber, and the first gas outlet opening is a through hole formed in a portion of the base plate facing the second chamber; and wherein the second gas outlet port is opened to discharge the combustion gas and a pressurized gas to the outside of the cylinder housing, and the second gas outlet port is a through hole formed in a portion of a peripheral wall of the cylinder housing forming the diffuser chamber.

[0012] The present disclosure provides a gas generator (the fifth aspect) comprising, in a cylinder housing, a combustion chamber filled with gas generating agents as a gas source, and a gas discharge port for discharging a gas generated by the combustion of the gas generating agents, wherein the combustion chamber contains an ignition device containing an igniter and closing a first end opening of the cylinder housing, a partition wall closing a second end opening on the side axially opposite the first end opening, and a perforated cylinder body arranged in an interior thereof; wherein the igniter comprises an igniter main body having an ignition portion and an igniter collar surrounding and holding the igniter main body; wherein the perforated cylinder body is arranged such that its first end surrounds the ignition portion of the igniter and its second end is arranged on the axially opposite side on the side of the partition wall; wherein an interior of the perforated cylinder body is a first chamber filled with a portion of the gas generating agents, and an exterior of the perforated cylinder body is a second chamber filled with the remaining gas generating agents; and wherein the gas outlet opening comprises a through hole formed in a portion of the partition wall facing the second chamber and a through hole formed in a portion of the cylinder housing facing the second chamber on the side of the partition wall. Short description of the drawings

[0013] The present invention will be more fully understood from the following detailed description and the accompanying drawings which are given by way of illustration only and thus are not limitative of the present invention, in which: [ Fig. 1] Fig. Figure 1 is a longitudinal sectional view of a gas generator according to the first aspect; [ Fig. 2] Fig. Figure 2 is a longitudinal sectional view of a gas generator according to the second aspect, not according to the invention as such; [ Fig. 3] Fig. 3 shows a longitudinal sectional view of a gas generator according to the fifth aspect; [ Fig. 4] Fig. Figure 4 is a longitudinal sectional view of a gas generator according to the third aspect; [ Fig. 5] Fig. Figure 5 is a longitudinal sectional view of a gas generator according to the fourth aspect; [ Fig. 6] Fig. Figure 6 is a partial longitudinal sectional view of a gas generator according to the fourth aspect, which is an embodiment different from that of Fig. 5 is; [ Fig. 7] Fig. Figure 7 is a partial longitudinal sectional view of a gas generator according to the fourth aspect, which is a still further embodiment different from that in Fig. 5 distinguishes; [ Fig. 8] is a partial sectional view (before starting) in the longitudinal direction of a gas generator according to the fourth aspect, which is yet another embodiment different from that of Fig. 5 distinguishes; and [ Fig. 9] Fig. 9 is a partial longitudinal sectional view showing a state after starting the Fig. 8 shows the gas generator. Detailed description of the invention

[0014] In the gas generator, which is Fig. 1 to Fig. As shown in Figure 4 of JP H11-78766 A, by delaying the combustion of the gas generating agent 2 in the outer combustion chamber G2, it is possible to control the deployment speed of the airbag. Therefore, the gas generating agent 2 in the outer combustion chamber G2 is less flammable than the gas generating agent 2 in the inner combustion chamber G1.

[0015] The present invention provides a gas generator including a combustion chamber filled with gas generating agents as a gas source in a cylinder housing, wherein the gas generator improves combustibility of the gas generating agents in the combustion chamber.

[0016] The cylinder housing is made of metal, such as iron or stainless steel, in a similar way to the cylinder housings of known gas generators.

[0017] A first end opening of the cylinder housing is closed by an ignition device comprising an igniter. The ignition device may comprise only an igniter or may be a combination of an igniter with a known booster charge or the like.

[0018] The igniter comprises an igniter main body having an ignition portion and a metallic igniter collar surrounding and holding the igniter main body.

[0019] A second end opening of the cylinder housing is closed by a partition wall made of a metal. The metal of the partition wall may be the same as or different from that of the cylinder housing. The partition wall and the cylinder housing (a peripheral wall) may be formed integrally.

[0020] An interior of the cylinder housing in which the first end opening and the second end opening are closed is a combustion chamber, and a perforated cylinder body is arranged therein.

[0021] The perforated cylinder body is formed of a metal, and the metal may be the same or different from that of the cylinder housing.

[0022] In the perforated cylinder body, an outer diameter and an inner diameter may be uniform or partially different. For example, the outer diameter of the perforated cylinder body may decrease from the first end toward the second end.

[0023] An arrangement of holes of the perforated cylinder body is not limited to any particular one, but may be formed as follows: the holes of the same size are evenly arranged between the first end and the second end (a formation density of the holes is uniform); the holes of the same size are irregularly formed between the first end and the second end (a formation density of the holes is not uniform); and the holes of different sizes are arranged between the first end and the second end.

[0024] The combustion chamber is divided into a first chamber in an interior space of the perforated cylinder body and a second chamber in an exterior space thereof, and both the first chamber and the second chamber are filled with gas generating agents.

[0025] The respective volumes of the first chamber and the second chamber can be the same or different.

[0026] The gas generating agents filled into the first chamber and the second chamber may be the same or different. If different gas generating agents are used for the first chamber and the second chamber, those that differ in at least one of composition, composition ratio, shape, and size may be used.

[0027] The gas outlet port is a through hole formed in the partition wall opposite to the second chamber, wherein the gas outlet port does not face the first chamber.

[0028] The gas outlet opening can be sealed with a sealing tape for moisture resistance.

[0029] A large number of gas generating agents are filled into the cylinder housing (the combustion chamber) of the gas generator. The gas generating agents are arranged in such a way that gaps are formed between the gas generating agents.

[0030] Each gas generating agent used therein is a shaped article formed into a desired shape such as a tablet, a column, or those having a recess or a through-hole.

[0031] Since the cylinder casing (combustion chamber) has an elongated shape, when the igniter is started at one end opening to ignite and burn the gas generating agents, the combustion proceeds sequentially from the gas generating agents located near the igniter toward the gas generating agents located away from the igniter.

[0032] However, when combustion occurs at an end opening and a combustion gas is generated, a compression phenomenon is likely to occur in the unburned gas generating agents, which are pressurized toward the end opening by the pressure of the combustion gas.

[0033] When such a compression phenomenon occurs, the spaces between the gas generating agents collapse, thereby hindering combustion gas flow and deteriorating the combustibility of the gas generating agents as a whole and the gas discharge efficiency.

[0034] In the gas generator of the present invention, the perforated cylinder body is arranged in the combustion chamber, the combustion chamber is divided into the first chamber on the inside and the second chamber on the outside, and the combustion gas flows into and out of the first chamber and the second chamber.

[0035] When the igniter at the first end of the perforated cylinder body is actuated to ignite and burn the gas generating agents in the first chamber, it is assumed that the compression phenomenon occurs in the gas generating agents in the first chamber and progression of combustion to the second end is hindered in the same manner as in the prior art.

[0036] However, according to the present invention, a combustion gas generated by the gas generating agents in the first chamber flows into the second chamber through the holes of the perforated cylinder body to burn the gas generating agents in the second chamber, and a combustion gas generated by the gas generating agents in the second chamber flows into the first chamber through the holes of the perforated cylinder body to burn the gas generating agents in an unburned portion in the first chamber, so that the combustion of the gas generating agents in the first chamber and the combustion of the gas generating agents in the second chamber assist each other.

[0037] Thus, the compression phenomenon described above does not occur, and ignitability, combustibility of the gas generating agents, and gas discharge performance are improved even when the gas generating agents are filled in the elongated combustion chamber.

[0038] Furthermore, in the gas generator according to the first aspect, even when the compression phenomenon occurs in a large number of gas generating agents in the combustion chamber (the first chamber), a gas flow path is ensured that has gaps between the gas generating agents. Therefore, the first aspect does not apply to a gas generator in which a small number, such as one or two, of the gas generating agents are filled in a combustion chamber, or a gas generator in which no gaps are formed between the gas generating agents, in other words, a gas generator in which the above compression phenomenon does not occur in the gas generating agents. The same also applies to each of the following aspects.

[0039] The gas outlet port of the gas generator according to the second aspect is a through hole formed in a portion of the cylinder housing facing the second chamber on the partition wall side.

[0040] Here, “the side of the partition wall” means a position of the gas outlet port, preferably at a length of 0.3 or less from the surface of the partition wall on the combustion chamber side, and more preferably at a length of 0.2 or less when a length from the first end opening of the cylinder casing to the surface, on the combustion chamber side, of the partition wall closing the second end opening is set to 1.

[0041] In the gas generator according to the third aspect, a diffuser portion is provided on the gas generator according to the first aspect, and the other components correspond to those of the first aspect.

[0042] The diffuser section itself can have a cup shape, as in conventional gas generators.

[0043] Separate members joined by welding or the like may be used as the diffuser portion, or the diffuser portion may be formed integrally with the cylinder housing.

[0044] The gas generator according to the third aspect includes a first gas outlet opening formed in the partition wall and a second gas outlet opening formed in the diffuser portion.

[0045] The second gas outlet opening may be formed in the bottom surface or in the peripheral wall of the cup-shaped diffuser.

[0046] The first gas outlet opening or the second gas outlet opening may be sealed with a sealing tape for moisture resistance.

[0047] According to the fourth aspect, gas generating agents and a compressed gas (argon, helium or the like) are used in combination as a gas source.

[0048] Therefore, a combustion chamber filled with the gas generating agents and a compressed gas chamber filled with the high-pressure compressed gas are provided, wherein a diffuser chamber is further provided between the combustion chamber and the compressed gas chamber.

[0049] Although the gas generator in which the combustion chamber, the diffuser chamber, and the pressurized gas chamber are arranged in this order is known, in the gas generator according to the fourth aspect, a chamber having the same structure as that in the first aspect is used as the combustion chamber.

[0050] According to the fourth aspect, a breaking device for a closing element closing between the diffuser chamber and the pressurized gas chamber is used similarly to the partition wall according to the first aspect and the third aspect.

[0051] The first gas outlet port is a through hole provided in the thickness direction of the base plate portion of the crushing device.

[0052] The second gas outlet port is a through hole formed in a peripheral wall of the cylinder housing forming the diffuser chamber.

[0053] The gas outlet port of the gas generator according to the fifth aspect includes an opening formed in the portion of the partition wall facing the second chamber and an opening formed in the portion of the cylinder housing facing the second chamber on the partition wall side.

[0054] Here, “the side of the partition wall” indicates a position of the gas outlet port, preferably at a length of 0.3 or less from the surface of the partition wall on the combustion chamber side, and more preferably at a length of 0.2 or less when a length from the first end opening of the cylinder casing to the surface, on the combustion chamber side, of the partition wall closing the second end opening is set to 1.

[0055] At the time of actuation, the same operation as in the first aspect is performed in the combustion chamber, and the combustion gas in the combustion chamber is discharged from the first gas discharge port into the diffuser chamber.

[0056] Furthermore, when the breaking device slides in the axial direction due to the pressure increase in the combustion chamber and the closing member is broken, a gas outlet path opens from the pressurized gas chamber to the diffuser chamber.

[0057] Thus, the combustion gas in the combustion chamber and the compressed gas in the compressed gas chamber penetrate into the diffuser chamber and are then discharged from the second gas outlet opening to the outside of the gas generator.

[0058] Preferably, in the gas generator according to the first aspect to the fourth aspect, a perforated cylinder body is used in which an opening area of ​​the holes increases from the first end toward the second end.

[0059] A method for producing the opening area of ​​the holes in the perforated cylinder body increasing from the first end toward the second end may comprise: a method in which a formation density of the holes increases continuously or stepwise from the first end toward the second end; and a process in which the size of the holes increases continuously or stepwise from the first end toward the second end.

[0060] In the case of stepwise enlargement, for example, a method is used such that the perforated cylinder body is divided longitudinally into several zones and the formation density or the size of the holes in each zone is changed.

[0061] Preferably, in the gas generators according to the first aspect to the fourth aspect, a volume (V1) of the first chamber of the combustion chamber and a volume (V2) of the second chamber satisfy a relationship of V2 > V1.

[0062] Since the gas outlet opening (the first gas outlet opening) faces the second chamber, the relationship V2 > V1 is preferably satisfied because a combustion gas flow becomes more uniform and the combustion of the gas generating agents is further promoted.

[0063] In the gas generator of the present invention, ignitability and combustibility of the gas generating agents filled in the elongated combustion chamber improve, and combustion gas is also easily discharged from the combustion chamber.

[0064] The gas generator of the present invention is used, for example, as a gas generator for an airbag device installed in a vehicle. Description of embodiments(1) The gas generator shown in Fig. 1

[0065] In a gas generator 1, a cylinder housing 10 formed of a metal such as iron or stainless steel is used.

[0066] A first end opening 10a of the cylinder housing 10 is closed by an igniter 11.

[0067] The igniter 11 comprises an igniter main body having an ignition portion 12 and an igniter collar 13 surrounding and holding the igniter main body.

[0068] An annular cushioning material 14 formed of a resin, a rubber, a wire mesh or the like is arranged around the ignition portion 12.

[0069] A second end opening 10b on the side axially opposite the first end opening 10a of the cylinder housing 10 is closed by a partition wall 15.

[0070] An interior of the cylinder housing 10 is a combustion chamber 20, and a perforated cylinder body 21 is arranged in the combustion chamber 20.

[0071] The perforated cylinder body 21 is arranged such that its first end 21a rests against the igniter collar 13 of the igniter 11 and surrounds the ignition section 12 of the igniter 11. In Fig. 1, the perforated cylinder body 21 rests against the igniter collar 13, although the perforated cylinder body does not have to rest against the igniter collar 13.

[0072] In the perforated cylinder body 21, a second end 21b is provided on the side axially opposite to the first end 21a, on the side of the partition wall 15.

[0073] The second end 21b may abut against a surface 15a of the partition wall 15 on the combustion chamber 20 side or may be provided opposite thereto with a small gap therebetween. The small gap is a gap equal to or smaller than a diameter of holes (a hole with the smallest diameter when the holes have different diameters) of the perforated cylinder body 21.

[0074] The second end 21b of the perforated cylinder body 21 may be fitted into an annular groove or a circular recess formed in the surface 15a of the partition wall 15 (the area in which the gas outlet openings 16 are not formed).

[0075] An interior of the perforated cylinder body 21 arranged in the combustion chamber 20 is a first chamber 22 filled with a part of gas generating agents (first gas generating agent 25), and an exterior of the perforated cylinder body 21 is a second chamber 23 filled with the remaining gas generating agent (second gas generating agent 26).

[0076] The first gas generating means 25 and the second gas generating means 26 may be the same, or they may be different from each other in a composition (a combination of fuel, oxidizer, and the like) and / or composition ratio (fuel ratio, an oxidizer ratio, and the like) and / or a shape and / or a size.

[0077] Although the first gas generating agents 25 and the second gas generating agents 26 are in the form of a tablet in Fig. 1, the gas generating means may have another shape, such as a columnar shape, and may further be formed with a recess and a through hole.

[0078] A cylinder body having a uniform outer diameter and inner diameter is used as the perforated cylinder body 21, but a cylinder body in which an outer diameter and an inner diameter decrease from the first end 21a toward the second end 21b may be used instead.

[0079] Preferably, a cylinder body in which the outer diameter and the inner diameter decrease from the first end 21a toward the second end 21b is used as the perforated cylinder body 21 because ignitability and combustibility in the initial stage of actuation of the igniter 11 are improved.

[0080] The perforated cylinder body 21 has a large number of through holes (gas passage holes) 27 in the peripheral wall. Fig. 1, the gas passage holes 27, which have the same size, are uniformly distributed.

[0081] An opening area of ​​the gas passage holes 27 may increase from the first end 21a toward the second end 21b.

[0082] Preferably, the opening area of ​​the gas passage holes 27 is enlarged from the first end 21a toward the second end 21b because ignitability and combustibility of the gas generating agents (the first gas generating agents 25 and the second gas generating agents 26) arranged away from the igniter 11 are improved.

[0083] The opening area is increased or decreased by adjusting a size or a formation density of the gas passage holes 27.

[0084] A volume (V1) of the first chamber 22 of the combustion chamber 20 and a volume (V2) of the second chamber 23 preferably have a relationship V2 > V1, and more preferably are within a range of V2 / V1 = 1.1 to 1.5.

[0085] When V2 > V1 and V2 / V1 = 1.1 to 1.5 are satisfied, ignitability and combustibility of the gas generating agents (the first gas generating agents 25 and the second gas generating agents 26) improve.

[0086] The gas outlet openings 16 are through holes formed in the partition wall 15 and are provided only in a part thereof facing the second chamber 23.

[0087] In the gas outlet openings 16, 4 to 8 through holes are arranged in a ring shape.

[0088] The gas outlet openings 16 can be closed with a metal sealing tape from the inside or from the outside.

[0089] In the following, an operation of the gas generator 1, which is Fig. 1 is shown.

[0090] When the igniter 11 is actuated, the first gas generating agents 25 in the first chamber 22 in front of the ignition section 12 are ignited and burned to produce a combustion gas.

[0091] The combustion gas generated in the first chamber 22 causes the combustion of the first gas generating agent 25 to proceed from the first end 21a to the second end 21b of the perforated cylinder body 21. At the same time, the combustion gas also flows from the gas passage holes 27 of the perforated cylinder body 21 into the second chamber 23 to ignite and burn the second gas generating agent 26.

[0092] At this time, unburned first gas generating agents 25 are located in a region near the partition wall 15 on the X-axis of the ignition portion 12, receive an ignition pressure and the like from the ignition portion 12, and are pressurized toward the partition wall 15.

[0093] A filling amount (a filling ratio) of the first gas generating agents 25 and the second gas generating agents 26 is adjusted according to a gas generating amount (a gas generating capacity) of the inflator 1, and, for example, several tens to several hundred of the gas generating agents are filled into the respective chambers. As a result, gaps form between the gas generating agents, and the aforementioned compression phenomenon caused by a shock at the time of ignition occurs in the first gas generating agents 25 in the first chamber 22.

[0094] As a result, the gaps between the first gas generating means 25 are reduced, and the gas does not easily flow toward the partition wall 15 along the axis X in the first chamber 22.

[0095] In the gas generator of the present invention, a part of the combustion gas generated in the first chamber 22 flows from the gas passage holes 27 into the second chamber 23 and ignites and burns the second gas generating means 26. At this time, since the compression phenomenon caused by the shock at the time of ignition does not occur in the second gas generating means 26, the combustion gas is immediately discharged from the gas outlet ports 16 facing the second chamber 23, so that blockage of the gas flow path is unlikely to occur.

[0096] The combustion gas in the second chamber 23 flows from the gas passage holes 27 of the perforated cylinder body 21 into the first chamber 22 and accelerates the combustion of the unburned first gas generating agents 25. At the same time, the combustion gas in the first chamber 22 flows from the gas passage holes 27 of the perforated cylinder body 21 into the second chamber 23 and is discharged from the gas outlet openings 16.

[0097] Thus, even if the aforementioned compression phenomenon occurs in the gas generating means in the region near the partition wall 15, combustion is supported by both the first gas generating means 25 and the second gas generating means 26. Consequently, the flow of the combustion gas becomes more uniform, and a combustion path up to the gas outlet ports 16 is ensured. (2) The gas generator shown in Fig. 2

[0098] One in Fig. 2, the gas generator 1A shown as such not in the invention corresponds to the one shown in Fig. 1, except that a position of the gas outlet openings 16a is different.

[0099] The gas outlet openings 16a are through holes formed in a portion of the cylinder housing 10 facing the second chamber 23 on the side of the partition wall 15.

[0100] When a length from the first end opening 10a of the cylinder housing 10 to the surface 15a on the combustion chamber 20 side of the partition wall 15 closing the second end opening 10b is set to 1, the gas outlet openings 16a are formed such that they are arranged at a length of 0.2 or less from the surface 15a of the partition wall on the combustion chamber side. Fig. 2 is the same as the gas generator shown in Fig. 1 is shown. (3) The gas generator shown in Fig. 3

[0101] One in Fig. 3 shown gas generator 1B is the same as that shown in Fig. 1, with the exception that the gas outlet openings 16 and the gas outlet openings 16a are provided.

[0102] The gas outlet openings 16 correspond to those of the gas generator 1, which is Fig. 1 is shown.

[0103] The gas outlet openings 16a correspond to those of the gas generator 1A, which is Fig. 2. Its operation corresponds to that of the gas generator shown in Fig. 1 is shown. (4) The gas generator shown in Fig. 4

[0104] One in Fig. The gas generator 1C shown in Figure 4 corresponds to the gas generator 1 shown in Fig. 1, except that a diffuser section 30 is provided.

[0105] The diffuser portion 30 is formed in a cup shape having a bottom surface 31, a peripheral wall 32 and an opening 33, and an inclined surface 34 having an inner diameter smaller on the side of the bottom surface 31 is provided between the opening 33 and the peripheral wall 32.

[0106] The diffuser section 30, which is in Fig. 4, has a plurality of second gas outlet openings 36 in the peripheral wall 32, but the gas outlet openings may also be provided in the bottom surface 31 or in both the bottom surface 31 and the peripheral wall 32.

[0107] The opening 33 of the diffuser portion 30 is welded to the second end opening 10b of the cylinder housing 10 (a welded portion 39).

[0108] In the Fig. 4, the through holes in the partition wall 15 are the first gas outlet openings 16, and a combustion gas generated in the combustion chamber 20 is discharged from the first gas outlet openings 16 into the diffuser section 30 and then discharged from the second gas outlet openings 36 to the outside of the gas generator 1C. The mechanism at the time of ignition of the igniter 11 to initiate the combustion The gas discharge rate from the first gas outlet openings 16 is the same as that of the gas generator, which is Fig. 1 is shown. (5) The gas generator shown in Fig. 5

[0109] In a gas generator 100, which is Fig. 5, a cylinder casing 101 obtained by assembling a combustion chamber casing 102 and a pressurized gas chamber casing 103 by welding is used.

[0110] A combustion chamber 110, a diffuser chamber 140, and a pressurized gas chamber 150 are provided in the order of description from a first end opening 102a of the cylinder housing 101 (the combustion chamber housing 102) toward a closing surface 105 at the second end opening of the cylinder housing 101 (the pressurized gas chamber housing 103) on the opposite side in the axial direction.

[0111] A metallic closing element 151 closes between the diffuser chamber 140 and the compressed gas chamber 150.

[0112] The first end opening 102a of the cylinder housing 101 (the combustion chamber housing 102) is closed by an igniter 111.

[0113] The igniter 111 has an igniter main body including an ignition portion 112 and a metallic ignition collar 113 surrounding and holding the igniter main body.

[0114] The side axially opposite the igniter 111 in the combustion chamber housing 102 is closed by a breaking device 130 for breaking the closing element 151.

[0115] An internal space between the igniter 111 and the breaking device 130 in the combustion chamber casing 102 is the combustion chamber 110, and a perforated cylinder body 120 is arranged in the combustion chamber 110.

[0116] The perforated cylinder body 120 is arranged such that its first end 120a rests against the igniter collar 113 of the igniter 111 and surrounds the ignition section 112 of the igniter 111. In Fig. 5, the perforated cylinder body 120 rests against the igniter collar 113, although the perforated cylinder body does not have to rest against the igniter collar 113.

[0117] In the perforated cylinder body 120, a second end 120b is arranged on the side axially opposite to the first end 120a, on the side of the breaking device 130.

[0118] The second end 120b abuts a surface 132a, on the combustion chamber 110 side, of a base plate portion 132 of the crushing device 130, or may be provided opposite thereto with a small gap therebetween. The small gap is equal to or smaller than a diameter of the gas passage holes 127 (a hole with the smallest diameter when the holes have different diameters) in the perforated cylinder body 120.

[0119] An interior of the perforated cylinder body 120 arranged in the combustion chamber 110 is a first chamber 122 filled with a part of the gas generating agent (first gas generating agent 125), and an exterior of the perforated cylinder body 120 is a second chamber 123 filled with the remaining gas generating agent (second gas generating agent 126).

[0120] The first gas generating means 125 and the second gas generating means 126 may be the same or different from each other in terms of a composition (a combination of fuel, oxidizer, and the like) and / or a composition ratio (a ratio of fuel, oxidizer, and the like) and / or a shape and / or a size.

[0121] Although the first gas generating agents 125 and the second gas generating agents 126 are in the form of a tablet in Fig. 5, the gas generating means may have another shape such as a columnar shape and may be further formed with a recess and a through hole.

[0122] A cylinder body having a uniform outer diameter and inner diameter is used as the perforated cylinder body 120, but a cylinder body in which an outer diameter and an inner diameter decrease from the first end 120a toward the second end 120b may be used instead.

[0123] Preferably, the cylinder body in which the outer diameter and the inner diameter decrease from the first end 120a toward the second end 120b is used as the perforated cylinder body 120 because ignitability, combustibility, and combustion gas discharge efficiency improve at an initial stage of actuation of the igniter 111.

[0124] The perforated cylinder body 120 has a large number of through holes (gas passage holes) 127 in the peripheral wall. Fig. 5, the gas passage holes 127, which have the same size, are evenly distributed.

[0125] An opening area of ​​the gas passage holes 127 may increase from the first end 120a toward the second end 120b.

[0126] Preferably, the opening area of ​​the gas passage holes 127 is formed to increase from the first end 120a toward the second end 120b because ignitability and combustibility of the gas generating means (the first gas generating means 125 and the second gas generating means 126) arranged away from the igniter 111 improve.

[0127] The opening area is increased or decreased by adjusting a size or a formation density of the gas passage holes 127.

[0128] A volume (V1) of the first chamber 122 of the combustion chamber 110 and a volume (V2) of the second chamber 123 preferably have a relationship of V2 > V1, and more preferably are within a range of V2 / V1 = 1.1 to 1.5.

[0129] When V2 > V1 and V2 / V1 = 1.1 to 1.5 are satisfied, ignitability, combustibility, and combustion gas discharge efficiency of the gas generating agents (the first gas generating agents 125 and the second gas generating agents 126) improve.

[0130] The breaking device 130 for breaking the closing element 151 is arranged in the diffuser chamber 140.

[0131] The crushing device 130 includes a base plate portion 132 having a plurality of through holes (first gas outlet ports) 131 in the thickness direction, and a crushing portion 133 provided vertically from a central portion of the base plate portion 132. A distal end 134 of the crushing portion 133 has a shape corresponding to a curved shape of the closure member 151.

[0132] A peripheral surface of the base plate portion 132 of the crushing device 130 abuts an inner wall surface of the combustion chamber housing 102.

[0133] The base plate portion 132 is supported from both sides in the x-axis direction by low protrusions formed at a distance in the axial direction on the inner wall surface of the combustor casing 102 so as to prevent them from slipping before operation.

[0134] A plurality of through holes (first gas outlet ports 131) are provided in the thickness direction in a surface of the base plate portion 132 in which the breaking portion 133 is not formed.

[0135] As the first gas outlet ports 131, 4 to 8 through holes are arranged in a ring shape so as to face the second chamber 123.

[0136] A plurality of second gas outlet openings 136 are arranged uniformly in a circumferential direction in a portion of the combustion chamber housing 102 facing the diffuser chamber 140.

[0137] A stopper 137 for stopping the sliding movement of the breaking device 130 (the base plate portion 132) in the X-axis direction at the time of operation is formed at a portion of the combustor casing 102 opposite to the diffuser chamber 140.

[0138] The stopper 137 is formed of a plurality of independent projections formed at equal intervals in the circumferential direction.

[0139] Gas, such as argon or helium, is injected into the pressurized gas chamber 150 at high pressure. After the gas is injected from a gas injection hole in the closing surface 105, the injection hole is closed by welding an inserted pin 106 and the closing surface 105 together.

[0140] In the following, an operation of the Fig. 5 described gas generator 100.

[0141] When the igniter 111 is actuated, the first gas generating agents 125 in the first chamber 122 in front of the ignition section 112 are ignited and burned to generate a combustion gas.

[0142] The combustion gas generated in the first chamber 122 causes the combustion of the first gas generating agent 25 to proceed from the first end 120a to the second end 120b of the perforated cylindrical body 120. At the same time, the combustion gas also flows from the gas passage holes 127 of the perforated cylindrical body 120 into the second chamber 123 to ignite and burn the second gas generating agent 126.

[0143] At this time, unburned first gas generating agents 125 are located in a region near the base plate portion 132 on the X-axis of the ignition portion 112, receive an ignition pressure and the like from the ignition portion 112, and are pressurized toward the base plate portion 132.

[0144] A filling amount (a filling number) of the first gas generating agents 125 and the second gas generating agents 126 is adjusted in accordance with a gas generating amount (a gas generating capacity) of the inflator 100, and, for example, approximately several tens to several hundred gas generating agents are filled into the respective chambers. Thus, gaps are formed between the gas generating agents, and the previously described compression phenomenon caused by a shock at the time of ignition occurs in the first gas generating agents 125 in the first chamber 122.

[0145] Accordingly, the gaps between the first gas generating means 125 are reduced, and the gas does not easily flow toward the base plate portion 132 along the X-axis in the first chamber 122.

[0146] In the gas generator of the present invention, a part of the combustion gas generated in the first chamber 122 flows from the gas passage holes 127 into the second chamber 123 and ignites and burns the second gas generating means 126. At this time, since the compression phenomenon caused by the shock at the time of ignition does not occur in the second gas generating means 126, the combustion gas is immediately discharged from the first gas outlet ports 131 facing the second chamber 123, and blockage of the gas flow path is unlikely to occur.

[0147] The combustion gas in the second chamber 123 flows from the gas passage holes 127 of the perforated cylinder body 120 into the first chamber 122 and accelerates the combustion of the unburned first gas generating agents 125. Simultaneously, the combustion gas in the first chamber 122 flows from the gas passage holes 127 of the perforated cylinder body 120 into the second chamber 123 and is discharged from the first gas outlet ports 131.

[0148] As a result of accelerating the combustion of both the first gas generating means 125 and the second gas generating means 126 as described above, a range in which the compression phenomenon described above occurs in the gas generating means is limited, and a flow of the combustion gas becomes more uniform.

[0149] Even if the compression phenomenon described above occurs in the gas generating means in the area near the base plate portion 132, combustion of both the first gas generating means 125 and the second gas generating means 126 is promoted. Consequently, the flow of the combustion gas becomes more uniform, and a combustion path up to the second gas outlet ports 136 is ensured.

[0150] As described above, when the combustion gas is generated by the first gas generating means 125 and the second gas generating means 126 in the combustion chamber 110 and a pressure in the combustion chamber 110 increases, the base plate portion 132 of the breaking device 130 is pressed and the breaking device 130 slides toward the pressurized gas chamber 150.

[0151] The breaking device 130 is stopped by colliding with the stopper 137 after the base plate portion 132 has moved a distance L.

[0152] When the breaking device 130 slides in this way, the closing member 151 closing between the diffuser chamber 140 and the pressurized gas chamber 150 is broken, a gas discharge path opens from the pressurized gas chamber 150 to the diffuser chamber 140, and the pressurized gas in the pressurized gas chamber 150 flows into the diffuser chamber 140.

[0153] Furthermore, the combustion gas generated by combustion of the first gas generating means 125 and the second gas generating means 126 in the combustion chamber 110 flows into the diffuser chamber 140 from the first gas discharge ports 131 formed in the base plate portion 132.

[0154] The combustion gas and the pressurized gas flowing into the diffuser chamber 140 are discharged from the second gas outlet ports 136 to the outside of the gas generator 100.

[0155] When the breaking device 130 slides by a distance L, and even if a gap of the distance L is formed between the second end 120b of the perforated cylinder body 120 and the base plate portion 132 of the breaking device, combustibility of the first gas generating means 125 and the second gas generating means 126 and discharge of the combustion gas from the first gas discharge ports 131 are not affected. (6) The gas generators shown in Fig. 6 and Fig. 7

[0156] One in Fig. 6 shown gas generator 100A and a Fig. 7 shown gas generator 100B differ from that shown in Fig. 5 in that a second end 120b of a perforated cylinder body 120 is fitted into a breaking device 130 (a base plate portion 132).

[0157] In the Fig. 6, a surface 132a of the base plate portion 132 on the side of a combustion chamber 110 has an annular groove 138a, and the second end 120b of the perforated cylinder body 120 is fitted into the annular groove 138a.

[0158] At the time of actuation, when the breaking device 130 (the base plate portion 132) slides by the distance L (see Fig. 5) the perforated cylinder body 120 also slides together with the base plate portion 132.

[0159] At this time, a gap is formed between a first end 120a of the perforated cylinder body 120 and an ignition portion 112 of an igniter. However, both the first gas generating agents 125 and the second gas generating agents 126 near the ignition portion 112 have already been combusted, and although a portion of the combustion gas flows through the gap between a first chamber 122 and a second chamber 123, the actuation itself is not affected.

[0160] In the Fig. In the gas generator 100B shown in Fig. 7, the surface 132a of the base plate portion 132 on the side of a combustion chamber 110 has a recess 138b having a circular planar shape, and a second end 120b of the perforated cylinder body 120 is fitted into the recess 138b.

[0161] At the time of actuation, when the breaking device 130 (the base plate portion 132) slides by the distance L (see Fig. 5) the perforated cylinder body 120 also slides together with the base plate portion 132.

[0162] At this time, a gap is formed between a first end 120a of the perforated cylinder body 120 and an ignition portion 112 of an igniter. However, both the first gas generating agents 125 and the second gas generating agents 126 near the ignition portion 112 have already burned, and although some of the combustion gas moves through the gap between the first chamber 122 and the second chamber 123, the actuation itself is not affected. (7) The gas generator shown in Fig. 8 and Fig. 9

[0163] A Fig. 8 and Fig. The gas generator 100C shown in Figure 9 differs from the one shown in Fig. 5 in that a mounting relationship of an igniter 111 and a first end 120a of a perforated cylinder body 120 is different, and in that a second end 120b of the perforated cylinder body 120 is fitted into a breaking device 130 (a base plate portion 132).

[0164] The perforated cylinder body 120 has an enlarged diameter portion 120c with an enlarged outer diameter at the first end 120a.

[0165] Compared to the Fig. 5, an outer diameter of a part of the igniter collar 113 is reduced.

[0166] As in Fig. 8, the enlarged diameter portion 120c of the first end 120a of the perforated cylinder body 120 is fitted into a part of the igniter collar 113.

[0167] As in Fig. 8, the second end 120b of the perforated cylinder body 120 is inserted into a recess 138b in the same manner as in Fig. 7 shown, fitted.

[0168] At the time of operation, when the breaking device 130 (the base plate portion 132) slides by a distance L1, the perforated cylinder body 120 also slides together with the base plate portion 132.

[0169] At this point, as in Fig. 9, a projection length from the igniter collar 113 to the ignition portion 112 is L2.

[0170] In the present embodiment, adjustment is carried out such that a relationship of the projection length L2 > the distance L1 is obtained. Thus, even if the breaking device 130 (the base plate portion 132) and the perforated cylinder body 120 are displaced by the distance L1, the first end 120a of the perforated cylinder body 120 surrounds the ignition section 112.

[0171] Thus, a first chamber 122 and a second chamber 123 are separated from each other, and movement of the combustion gas between the first chamber 122 and the second chamber 123 occurs only via the gas passage holes 127.

Claims

[1] Gas generator (1) comprising, in a cylinder housing (10), a combustion chamber (20) filled with gas generating means (25, 26) as a gas source, and a gas outlet opening (16) for expelling a gas generated by the combustion of the gas generating means (25, 26), wherein the combustion chamber (20) contains an ignition device containing an igniter (11) and closing a first end opening (10a) of the cylinder housing (10), a partition wall (15) closing a second end opening (10b) on the side axially opposite the first end opening (10a), and a perforated cylinder body (21) arranged in the combustion chamber (20); wherein the igniter (11) comprises an igniter main body having an ignition portion (12) and an igniter collar (13) surrounding and holding the igniter main body; wherein the perforated cylinder body (21) is arranged such that its first end (21a) surrounds the ignition section (12) of the igniter (11) and its second end (21b) is arranged on the axially opposite side on the side of the partition wall (15); wherein an interior of the perforated cylinder body (21) is a first chamber (22) filled with a portion of the gas generating means (25), and an exterior of the perforated cylinder body (21) is a second chamber (23) filled with the remaining gas generating means (26); and at least one gas outlet opening (16) is a through hole formed in a portion of the partition wall (15) facing the second chamber (23), and no gas outlet opening is formed in a region of a length of more than 0.3 from the surface of the partition wall (15) on the combustion chamber (20) side toward the first end opening (10a) in a portion of the cylinder housing (10) facing the second chamber (23) when a length from the first end opening (10a) of the cylinder housing (10) to the surface, on the combustion chamber (20) side, of the partition wall (15) closing the second end opening (10b) is set to 1, wherein the second end (21b) abuts against a surface (15a) of the partition wall (15) on the combustion chamber (20) side or is provided opposite thereto with a small gap therebetween, the small gap being a gap equal to or smaller than a diameter of holes of the perforated cylinder body (21). [2] Gas generator (1C) according to claim 1, wherein a diffuser portion (30) is arranged at the second end opening (10b) of the cylinder housing (10) which is closed by the partition wall (15); wherein the gas outlet opening (16) is a first gas outlet opening and a second gas outlet opening (36) is provided which is formed in the diffuser section (30); and wherein a combustion gas generated in a combustion chamber is discharged from the first gas outlet opening (16) into the diffuser section (30) and then discharged from the second gas outlet opening (36). [3] Gas generator (1B) according to claim 1, wherein the gas generator (1B) additionally comprises a cylinder housing gas outlet opening (16a) which is a through hole formed in a portion of the cylinder housing (10) facing the second chamber (23) on the side of the partition wall (15), the cylinder housing gas outlet opening (16a) is positioned at a length of 0.3 or less from the surface of the partition wall (15) on the side of the combustion chamber (20). [4] The gas generator (1) according to claim 1, wherein a perforated cylinder body (21) is used in which an opening area (27) of the holes increases from the first end to the second end. [5] Gas generator (1) according to claim 1, wherein a volume (V1) of the first chamber (22) of the combustion chamber (20) and a volume (V2) of the second chamber (23) satisfy a relationship V2 > V1. [6] Gas generator (1) according to claim 1, wherein the perforated cylinder body (21) has an outer diameter and an inner diameter that decreases from the first end to the second end. [7] A gas generator (1) according to claim 1, wherein a large number of gas generating means (25, 26) are filled in the first chamber (22) and in the second chamber (23), and wherein the gas generating means (25, 26) are arranged so that spaces are formed between the gas generating means (25, 26).

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